The inferred color index of the sun

Gray, David F.

doi:10.1086/133086

Cited by 23 publications

(19 citation statements)

References 8 publications

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“…In the Bus taxonomy scheme (Bus 1999;Bus and Binzel 2002), the only flat visible spectra (usually (Croft et al 1972;Tedesco et al 1982b;Gray 1992;Straizys and Valiauga 1994). provided by normalization to 1.0 at 500 nm) are those of Cb-and B-class asteroids (Fig. 2), where B class in the Tholen classification does not necessarily represent the same objects as B class in the Bus classification.…”

Section: Retrieving Reflectance Spectra From Asteroids Taxonomic Datamentioning

confidence: 99%

Almahata Sitta (=asteroid 2008 TC₃) and the search for the ureilite parent body

Jenniskens

Vaubaillon

Binzel

et al. 2010

Meteorit & Planetary Scien

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Abstract-This article explores what the recovery of 2008 TC 3 in the form of the Almahata Sitta meteorites may tell us about the source region of ureilites in the main asteroid belt. An investigation is made into what is known about asteroids with roughly the same spectroscopic signature as 2008 TC 3 . A population of low-inclination near-Earth asteroids is identified with spectra similar to 2008 TC 3 . Five asteroid families in the Main Belt, as well as a population of ungrouped asteroids scattered in the inner and central belts, are identified as possible source regions for this near-Earth population and 2008 TC 3 . Three of the families are ruled out on dynamical and spectroscopic grounds. New near-infrared spectra of 142 Polana and 1726 Hoffmeister, lead objects in the two other families, also show a poor match to Almahata Sitta. Thus, there are no Main Belt spectral analogs to Almahata Sitta currently known. Space weathering effects on ureilitic materials have not been investigated, so that it is unclear how the spectrum of the Main Belt progenitor may look different from the spectra of 2008 TC 3 and the Almahata Sitta meteorites. Dynamical arguments are discussed, as well as ureilite petrogenesis and parent body evolution models, but these considerations do not conclusively point to a source region either, other than that 2008 TC 3 probably originated in the inner asteroid belt.

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Section: Retrieving Reflectance Spectra From Asteroids Taxonomic Datamentioning

confidence: 99%

Almahata Sitta (=asteroid 2008 TC₃) and the search for the ureilite parent body

Jenniskens

Vaubaillon

Binzel

et al. 2010

Meteorit & Planetary Scien

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“…One of the latest is that of Gray (1992). The B -V values for the Sun are spread between 0.62 and 0.68!…”

Section: Color Of the Sunmentioning

confidence: 99%

Photometric calibrations of the effective temperature

Hauck¹,

Kunzli²

1996

Open Astronomy

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“…The main reasons for this in photometry and spectrophotometry are the difficulties in geometrically treating the solar image and scattered light; the immense flux difference between the Sun and stars, a factor of ∼10 11 ; and the impossibility of observing the Sun at night, which taxes the stability of instrumentation. The photometric properties of the Sun in the various photometric systems in use, thus, remain uncertain despite protracted efforts employing a variety of direct and indirect methods (e.g., Tüg & Schmidt-Kaler 1982;Hayes 1985;Saxner & Hammarbäck 1985;Neckel 1986;Friel et al 1993;Gray 1992Gray , 1994Porto de Mello & da Silva 1997;Ramírez & Meléndez 2005b;Holmberg et al 2006;Casagrande et al 2006;Meléndez et al 2010, and many others). A&A 563, A52 (2014) The identification of stars closely resembling the Sun plays an extremely interesting role in this task (Cayrel de Strobel 1996) and raises considerable interest on diverse astrophysical fronts.…”

Section: Introductionmentioning

confidence: 99%

A photometric and spectroscopic survey of solar twin stars within 50 parsecs of the Sun

Mello

Silva

et al. 2014

A&A

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Context. Solar twins and analogs are fundamental in the characterization of the Sun's place in the context of stellar measurements, as they are in understanding how typical the solar properties are in its neighborhood. They are also important for representing sunlight observable in the night sky for diverse photometric and spectroscopic tasks, besides being natural candidates for harboring planetary systems similar to ours and possibly even life-bearing environments. Aims. We report a photometric and spectroscopic survey of solar twin stars within 50 parsecs of the Sun. Hipparcos absolute magnitudes and (B − V)Tycho colors were used to define a 2σ box around the solar values, where 133 stars were considered. Additional stars resembling the solar UBV colors in a broad sense, plus stars present in the lists of Hardorp, were also selected. All objects were ranked by a color-similarity index with respect to the Sun, defined by uvby and BV photometry. Methods. Moderately high-resolution, high signal-to-noise ratio spectra were used for a subsample of equatorial-southern stars to derive T eff , log g (both ionization and evolutionary), and spectroscopic [Fe/H] with average internal errors better than 50 K, 0.20 dex, and 0.08 dex, respectively. Ages and masses were estimated from theoretical HR diagrams. Results. The color-similarity index proved very successful, since none of the best solar-analog and twin candidates that were photometrically and spectroscopically found to be good solar matches differed from the Sun by more than 3σ in their colors. We identify and quantitatively rank many new excellent solar analogs, which are fit to represent the Sun in the night sky to varying degrees of accuracy and in a wide range of contexts. Some of them are faint enough (V Tycho ∼ 8.5) to be of interest for moderately large telescopes. We also identify two stars with near-UV spectra indistinguishable from the Sun's, although only HD 140690 also has atmospheric parameters matching the Sun's, besides a high degree of photometric fidelity. This object is proposed as a prime solar analog in both the UV and visible ranges, a rare object. We present five new "probable" solar twin stars, besides five new "possible" twins, the best candidates being HD 98649, HD 118598, HD 150248, and HD 164595. Masses and isochronal ages for the best solar twin candidates lie very close to the solar values within uncertainties, but chromospheric activity levels range somewhat. We propose that the solar twins be emphasized in the ongoing searches for extra-solar planets and SETI searches.

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The inferred color index of the sun

Abstract: The high temperature sensitivity of the line-depth ratio V 1/16251.83 to Fe I A6252.57, measured in the daytime sky, is used to infer the color indices of the Sun: B-V=0.656±0.005, £-j;=0.414± 0.003, and B2-VI =0.393±0.004.

Cited by 23 publications

References 8 publications

Almahata Sitta (=asteroid 2008 TC₃) and the search for the ureilite parent body

Almahata Sitta (=asteroid 2008 TC₃) and the search for the ureilite parent body

Photometric calibrations of the effective temperature

A photometric and spectroscopic survey of solar twin stars within 50 parsecs of the Sun

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The inferred color index of the sun

Abstract: The high temperature sensitivity of the line-depth ratio V 1/16251.83 to Fe I A6252.57, measured in the daytime sky, is used to infer the color indices of the Sun: B-V=0.656±0.005, £-j;=0.414± 0.003, and B2-VI =0.393±0.004.

Cited by 23 publications

References 8 publications

Almahata Sitta (=asteroid 2008 TC3) and the search for the ureilite parent body

Almahata Sitta (=asteroid 2008 TC3) and the search for the ureilite parent body

Photometric calibrations of the effective temperature

A photometric and spectroscopic survey of solar twin stars within 50 parsecs of the Sun

Contact Info

Product

Resources

About

Almahata Sitta (=asteroid 2008 TC₃) and the search for the ureilite parent body

Almahata Sitta (=asteroid 2008 TC₃) and the search for the ureilite parent body